Fluid detergent products, such as liquids, gels, pastes and the like, are preferred by many consumers over solid detergents. Fluid detergent products may contain surfactants, e.g., anionic surfactants, and one or more solvents, in addition to water. Solvents may provide a variety of benefits: solvents may allow for the formulation of anionic surfactant-rich surfactant systems, particularly for compacted fluid detergents; solvents may adjust the viscosity of a formulation; solvents may allow for the formulation of an isotropic and physically stable formulation; and solvents may allow for the formulation of enzymes, polymers, bleach, chelants, and other ingredients that improve cleaning. Solvents may also be used to formulate stable, shippable, anionic surfactant concentrates, which may be combined downstream with other detergent ingredients to form a final detergent product. Also, some fluid detergent forms, such as fluid unit dose articles, may contain high levels of anionic surfactant and high levels of solvent, such as 30% or more solvent by weight of the total formulation.
Known solvents for use in fluid detergent formulations include 1,2-propane diol (p-diol), ethanol, diethylene glycol (DEG), 2-methyl-1,3-propanediol (MPD), dipropylene glycol (DPG), oligamines (e.g., diethylenetriamine (DETA), tetraethylenepentamine (TEPA), and glycerine (which may, for example, be used in fluid unit dose articles). However, these known solvents all have significant disadvantages, particularly if used at increased levels, including cost, formulatability, dissolution rate, solubility/stability of film in certain fluid unit dose articles, and potential adverse effects on cleaning and/or whiteness. Thus, there remains an ongoing need to identify new solvents that may allow for the formulation of increased concentrations of anionic surfactants in fluid detergent compositions, particularly compact fluid detergent compositions and concentrated surfactant pastes, and may address one or more of the disadvantages of known solvents discussed above.
Separately, a long-chain polyether polyol having a molecular weight of more than about 1,200 g/mole and produced by alkoxylating an initiator with an alkylene oxide in the presence of a basic catalyst having at least one cation thereof chelated with a polyoxyethylene-containing compound having a functionality of at least about three is known. Suitable initiator (or starter) compounds include, but are not limited to, C1-C30 monols, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, neopentyl glycol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 2.3-butanediol, 1,6-hexanediol, glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, α-methylglucoside, sorbitol, mannitol, hydroxymethylglucoside, hydroxypropylglucoside, sucrose, N,N,N′,N′-tetrakis[2-hydroxyethyl or 2-hydroxypropyl]ethylene diamine, 1,4-cyclohexanediol, cyclohexanedimethanol, hydroquinone, resorcinol, and the like. The long-chain polyether polyol may be used to provide a flexible polyurethane foam.
The alkoxylation of 2-methyl-1,3-propanediol is known; ethoxylated as well as propoxylated 2-methyl-1,3-propanediol are known. 1,4-butanediol ethoxylated is also known.
It has been found that the ethoxylated diols of formula (I) provide a better performing solvent in a fluid detergent product. Furthermore, it has been found that the ethoxylated diols of formula (I) perform better than many existing solvents used in detergent formulations and surfactant pastes, such as 1,2-propylene glycol and dipropylene glycol.